libinstaller/lib/sort.py

def topological_sort(source):
    pending = [(name, set(deps)) for name, deps in source]
    emitted = []
    while pending:
        next_pending = []
        next_emitted = []
        for entry in pending:
            name, deps = entry
            deps.difference_update(set((name,)), emitted)  # <-- pop self from dep, req Py2.6
            if deps:
                next_pending.append(entry)
            else:
                yield name
                emitted.append(name)  # <-- not required, but preserves original order
                next_emitted.append(name)
        if not next_emitted:
            raise ValueError("cyclic dependancy detected: %s %r" % (name, (next_pending,)))
        pending = next_pending
        emitted = next_emitted
    return emitted


def sort_libs_by_dependencies(selected_libs):
    deplist = []
    for lib in selected_libs:
        name = lib['name']
        dependencies = set(lib['dependencies'].split(','))
        if dependencies == {''}:
            dependencies = {}
        deplist.append([name, dependencies])
    sorted_deplist = topological_sort(deplist)
    sorted = []
    for entry in sorted_deplist:
        for lib in selected_libs:
            if lib['name'] == entry:
                sorted.append(lib)
    return sorted